The healthy resident gut microflora comprises a host of beneficial bacteria, predominantly members of the genera Lactobacillus and Bifidobacterium. The balance of microorganisms can be disrupted by infection, by alteration in diet, through antibiotic treatment, and by stress or physiological trauma. When this occurs a number of adverse reactions may be triggered. Digestive patterns may be altered, with occurrence of diarrhea, constipation and other symptoms of gut irritability. The immune system may be compromised, with consequent reduced resistance to infectious diseases. Pathogenic bacteria or fungi make take hold and colonise the digestive system or other parts of the body.
Traditionally, fermented milk products such as yogurts have been regarded as healthy foods capable of soothing the digestive system; this observation is now explained by the presence of lactic bacteria. Microorganisms such as Lactobacilli and Bifidobacteria which can promote health are termed “probiotics”. Research has shown that particular probiotic microorganisms can influence the composition of the gut microflora by competing out pathogenic bacteria and yeast. Probiotics are also alleged to promote healing of the intestinal mucosa, for example in patients with milk allergy, by reducing gut permeability and by enhancing local intestinal immune responses. Use of probiotics has been advocated for prophylaxis and treatment of diarrhea and for enhancing the recovery of commensal flora after antibiotic therapy. Anticarcinogenic activity has also been demonstrated in clinical trials with probiotics.
A number of “live” dairy products on the market are claimed to contain particularly high counts of certain probiotic Lactobacilli or Bifidobacteria species for promotion of digestion and a healthy immune system. However, the full range of desirable probiotic effects is exhibited by only a selected few strains of bacteria. It must also be borne in mind that the survivability of a strain in the gastrointestinal (GI) tract is crucial for the biological efficacy of that strain in situ. In order for the strain to implant and establish itself in the intestine it should ideally adhere to the mucosal surface of the GI tract and be able to survive the rigours of transit, such as exposure to stomach and bile acids.
The present invention concerns a novel probiotic strain of Lactobacillus, termed Lactobacillus pentosus LPK, which was deposited 28 Aug. 2001 according to the Budapest Treaty at the NCIMB, Aberdeen, UK and has received the accession number NCIMB 41114. In addition to exhibiting characteristics typical of Lactobacilli in general, this strain has a further surprising property: it is capable of suppressing the growth of Candida species to a degree never previously achieved through use of a probiotic. Furthermore, tetracycline and related antibiotics have no effect on growth of this strain. This unique combination of properties can be exploited to combat undesirable growth of Candida in any region of the body. In particular, since Candida is considered to be a causative factor in Irritable Bowel Syndrome (IBS), it is envisaged that this novel strain of L. pentosus could be employed in treating or preventing that disorder.